Equilibria and mesomerism/valence tautomerism of group 4 metallocene complexes

2020 ◽  
Vol 49 (7) ◽  
pp. 2119-2139 ◽  
Author(s):  
Uwe Rosenthal
Keyword(s):  
Experimental Results ◽  
Valence Tautomerism ◽  
Group 4 ◽  
Metallocene Complexes

Priority of equilibrium: reactivity of unusual group 4 metallocene complexes is best explained by the equilibrium and only additionally by the mesomerism/valence tautomerism. The equilibrium predominates the empirically found experimental results.

Synthesis and characterization of Group 4 metallocene complexes with two disiloxanediyl bridges

2000 ◽  
Vol 595 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Jaehoon Jung ◽  
Seok Kyun Noh ◽  
Dong-ho Lee ◽  
Sung Keun Park ◽  
Hyunjoon Kim
Keyword(s):  
Synthesis And Characterization ◽  
Group 4 ◽  
Metallocene Complexes

New alkenyl-substituted group 4 C-ansa-metallocene complexes. Reactivity of the substituent at the carbon ansa bridge

2009 ◽  
Vol 694 (13) ◽  
pp. 1959-1970 ◽  
Author(s):  
Antonio Antiñolo ◽  
Rafael Fernández-Galán ◽  
Noelia Molina ◽  
Antonio Otero ◽  
Iván Rivilla ◽  
...  
Keyword(s):  
Group 4 ◽  
Metallocene Complexes

A Fulvene Route to Group 4 Metallocene Complexes Bearing 4,7-Bis(dimethylamino)-Substituted Indenyl Ligands

2004 ◽  
Vol 2004 (11) ◽  
pp. 2260-2265 ◽  
Author(s):  
Jesus Cano Sierra ◽  
Sierra Gerald Kehr ◽  
Roland Fröhlich ◽  
Gerhard Erker
Keyword(s):  
Group 4 ◽  
Metallocene Complexes

scholarly journals Cover Picture: Reactions of Group 4 Metallocene Complexes with Mono- and Diphenylacetonitrile: Formation of Unusual Four- and Six-Membered Metallacycles (Chem. Eur. J. 13/2013)

2013 ◽  
Vol 19 (13) ◽  
pp. 4081-4081
Author(s):  
Lisanne Becker ◽  
Vladimir V. Burlakov ◽  
Perdita Arndt ◽  
Anke Spannenberg ◽  
Wolfgang Baumann ◽  
...  
Keyword(s):  
Group 4 ◽  
J 13 ◽  
Metallocene Complexes

Dinitrogen Borylation with Group 4 Metallocene Complexes

2013 ◽  
Vol 2013 (22-23) ◽  
pp. 3907-3915 ◽  
Author(s):  
Scott P. Semproni ◽  
Paul J. Chirik
Keyword(s):  
Group 4 ◽  
Metallocene Complexes

scholarly journals Synthesis, APPI Mass-Spectrometric Characterization and Polymerization Studies of Group 4 Dinuclear Bis(ansa-metallocene) Complexes

2018 ◽  
Author(s):  
Gilles Schnee ◽  
Mathilde Farenc ◽  
Leslie Bitard ◽  
Aurelien Vantomme ◽  
Alexandre Welle ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Mass Spectrometric ◽  
Spectrometric Data ◽  
Molecular Weights ◽  
Group 4 ◽  
Dinuclear Compounds ◽  
First Time ◽  
Metallocene Complexes ◽  
Catalytic Performances

New ligand platforms of the type p- or m-Ph{-CR(3,6-tBu2Flu)(Cp)}2 (para-, R = Me (2a), H (2b); meta-, R = Me (2c)) were synthesized via nucleophilic addition of the 3,6-tBu2-fluorenyl-anion onto the parent phenylene-bridged difulvenes (1a‒c). The corresponding discrete homodinuclear zirconium and hafnium bis(dichloro ansa-metallocene) complexes, Ph[{-CR(3,6-tBu2Flu)(Cp)}MCl2]2 (p-, R = Me (3a-Zr2, 3a-Hf2), R = H (3b-Zr2); m-, R = Me (3c-Zr2) were prepared by salt metathesis reactions. An attempt to generate in situ a heterodinuclear complex 3a-Zr-Hf was also undertaken. For the first time, Atmospheric Pressure PhotoIonization (APPI) mass-spectrometric data were obtained for all dinuclear compounds and found to be in excellent agreement with the simulated ones. Preliminary studies on the catalytic performances of these dinuclear complexes, upon activation with MAO, in ethylene homopolymerization and ethylene/1-hexene copolymerization revealed a few differences as compared to those of the monometallic analogues. In particular, slightly lower molecular weights and greater formation of short methyl and ethyl branches were obtained with the dinuclear systems.

Synthesis and Characterization of Multiferrocenyl-Substituted Group 4 Metallocene Complexes

2012 ◽  
Vol 18 (40) ◽  
pp. 12672-12680 ◽  
Author(s):  
Katharina Kaleta ◽  
Frank Strehler ◽  
Alexander Hildebrandt ◽  
Torsten Beweries ◽  
Perdita Arndt ◽  
...  
Keyword(s):  
Synthesis And Characterization ◽  
Group 4 ◽  
Metallocene Complexes

A Review on Molecular Electrochemistry of Metallocene Dichloride and Dimethyl Complexes of Group 4 Metals: Redox Properties and Relation with Optical Ligand-to-Metal Charge Transfer Transitions

2001 ◽  
Vol 66 (2) ◽  
pp. 185-206 ◽  
Author(s):  
Galina V. Loukova ◽  
Vladimir V. Strelets
Keyword(s):  
Charge Transfer ◽  
Metal Ion ◽  
Energy Gap ◽  
Optical Transition ◽  
Electrochemical Techniques ◽  
Redox Potentials ◽  
Metal Charge ◽  
Group 4 ◽  
Metal Charge Transfer ◽  
Metallocene Complexes

Emphasis is given to redox, photophysical, and photochemical properties of homologous bent metallocenes of group 4 transition metals. Comparative analysis of a variety of electron-transfer induced transformations and ligand-to-metal charge-transfer excited states is performed for bent metallocene complexes upon systematic variation of the identity of the metal ion (Ti, Zr or Hf), ancillary π- and monodentate σ- (Cl, Me) ligands. For such organometallic π-complexes, linear correlations exist between energies of optical and redox HOMO-to-LUMO electron transitions. It is suggested that combination of spectroscopic and electrochemical techniques provides important diagnostics to determine "ionisation potential" and "electron affinity" in solution (relative energies of frontier molecular orbitals obtained as redox potentials) and the energy gap in metallocene complexes. Some of earlier instructive cases of direct relationship between optical transition energies and differences in redox potentials revealed for inorganic and coordination compounds are discussed.

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